Mice were tested using both click (broadband noise) and tone pip (frequency specific) ABR. At P21 (A), WT mice (circles) and dCKO mice (triangles), there were no noticeable differences between the two groups and both groups had their most sensitive hearing at 16 kHz. At four months of age (B), both groups performed worse than P21 mice, and both groups were equivalent or near equivalent at both the click response and 16 kHz. When assessing the difference between the means of P21 and four month WT and dCKO (C), there was a significant increase in threshold for both groups at click; however, both groups had nearly identical threshold shifts.